| This is not the normal at all. What do you mean by not working?
How many machines do you have connected on the internal network?
If you mean that the router is loosing connection to the internet, how do you know it's the router and not the computer?
Assuming it is the router, how well is it ventilated? If theres a large build up of heat, that could cause the loss of a connection, but if you turn it on and after 3-4 hours it looses from a cold start, then the router may be malfunctioning.
Have you researched whether there is a firmware update? |